Grape plant named RS-9

ABSTRACT

A new and distinct grape ( Vitis vinifera  L. species), RS-9, which is useful as a rootstock, is distinguished by providing broad resistance to nematodes.

LATIN NAME OF GENUS AND SPECIES CLAIMED

‘RS-9’ is an interspecific variety of Vitis champinii×( Vitisriparia×Vitis rupestris)

VARIETY DENOMINATION

The name of the variety claimed is ‘RS-9’.

BACKGROUND OF THE INVENTION

The invention relates to a new and distinct variety of the Vitis L. withbroad nematode resistance.

The new variety, ‘RS-9’, is the result of an interspecific cross of thegrape varieties “Ramsey” (Vitis champinii) and “Schwarzmann” (Vitisriparia×Vitis rupestris). ‘RS-9’ plants were asexually reproduced inParlier. Calif. by the rooting of callused cuttings from dormant,lignified canes in spring or the rooting of green shoots undergreenhouse mist in summer.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a novel grape variety having thecharacteristics described and illustrated herein. ‘RS-9’ exhibits broadresistance to nematodes and can be used as a rootstock.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a close-up photo of the ‘RS-9’ shoot tip.

FIG. 2 illustrates a two-node section of primary shoot (upper, exposedside of mid shoot) with leaves attached far left), section of primaryshoot (lower, non-exposed side) (far right), and lateral shoot from thesame portion of the primary shoot (center of photo).

FIG. 3 illustrates an upper (left) and lower (right) sides of leavesfrom a primary ‘RS-9’ shoot.

FIG. 4 illustrates a ‘RS-9’ trailing shoot attached to a trellis wire.

DETAILED DESCRIPTION OF THE INVENTION

‘RS-9’ is a rootstock with vigor equivalent to variety Schwarzmann.‘RS-9’ is particularly suitable for evaluation in close-plantedsituations and for coastal valleys and coarse-textured soils.

‘RS-9’ seedlings readily strike roots and appear generally compatiblewith scions evaluated thus far.

‘RS-9’ demonstrates resistance to a gall-initiating Meloidogyne arenariapathotype from grape ‘Harmony’ and a non-galling M chitwoodi that alsoattacks ‘Harmony’. ‘RS-9’ exhibits good resistance to Xiphenema index,and Pratylenchus vulnus, and slight susceptibility to citrus nematode.

‘RS-9’ offers broader nematode resistance than ‘VR 039-16’, ‘Freedom’,‘Harmony’, ‘Ramsey’ or ‘Teleki 5C ’. Pre- and post-infection resistancemechanisms expressed by Vitis rootstocks ‘RS-9’ and ‘Teleki 5C’against-second-stage juveniles (J2) of resistance-breaking populationsof Meloidogyne arenaria were observed and correlated with juveniledevelopment and nematode reproduction. See, Table 1. Cabernet Sauvignongrape was used as a susceptible control for comparison. Similar numbersof J2 penetrated ‘Teleki 5C’ and Cabernet Sauvignon roots. Root-tipnecrosis, a hypersensitive reaction, occurred in both rootstocks but waseffective in reducing J2 penetration only in ‘RS-9’ roots. Juveniledevelopment occurred in roots of all three rootstocks by 13 days afterinoculation, with the highest number of swollen juveniles present inCabernet Sauvignon roots. Cortical necroses restricted the ability of J2to reach vascular bundles, thereby restricting access to successfulfeeding sites and leading to dead or underdeveloped juveniles in ‘RS-9’roots. At 35 days after inoculation, only 5% and 25% of the initialinoculum in ‘RS-9’ and ‘Teleki 5C’ roots, respectively, reached theadult stage compared to 32% in Cabernet roots. Giant cells were ofsufficient size to support nematode development to maturity in Cabernet.Cell necrosis and underdeveloped giant cells were apparent in theresistant rootstocks, which delayed development of adults and limitedegg production. TABLE 1 Penetration and development of aresistance-breaking population of Meloidogyne arenaria in roots of threegrape rootstocks. Nematodes per root system Days after inoculationRootstocks 4 13 21 27 35 Eggs/g root Cabernet (check) 296 a 294 a 272 a225 a 173 a 403 a ′Teleki-5′c 282 a 254 a 232 a 183 b 128 b  34 c ′RS-9′ 52 b  88 b  49 b  38 c  25 c  81 bData are means of five replications. Means in a column followed by acommon letter are not significantly different according to Duncan'smultiple range test (P = 0.05).

A botanical description of the ‘RS-9’ is provided below based onobservations and measurements made during the period of April 10 to Aug.1, 2003 at the University of California Kearney Agricultural Center,9240 S. Riverbend Avenue, Parlier, Calif. 93648 (Riverbend Avenue,between Manning and Dinuba Avenues, Fresno County). RS-9 rootstock wasapproximately 10 years old when observed. The vines were irrigated bydrip irrigation and row centers were cultivated by disk twice each year.Berms were hand hoes or treated with paraquat contact spray.

Color terminology used in the following description is based on thescheme described in Aloy, John Maerz and M. Rea Paul. A dictionary ofcolor, 2^(nd) edition. McGraw-Hill Book Co., New York, 1950. Descriptorsfor the guidelines for GRAPEVINE (Vitis. L), International Union for theProtection of New Varieties of Plants, Geneva, Switzerland are provided.

-   Vine: Vigorous, semi-drooping in attitude (U.P.O.V. — 6.1.5/7). The    canopy becomes bushy past midsummer due to numerous, lateral shoots    with small leaves. Bud burst early (U.P.O.V. — 7.1.2/3)-   Shoots:    -   -   Shoot tip.—Half open (U.P.O.V. — 6.1.1/3), downy white.        -   Young leaves.—Light green (U.P.O.V. — 6.1.16/1)(Plate 17,            I-7) with slight bronzing on tips of serrations; glabrous            except for white (U.P.O.V. — 6.1.2/1), sparse, prostrate            hairs on main veins on lower side (U.P.O.V. — 6.1.3/3).        -   Internodes.—Red (Plate 7, C-6) on the exposed, dorsal side            (U.P.O.V. — 6.1.6/3) and red (Plate 5, I-5) with green            stripes on the ventral side (U.P.O.V. — 6.1.7/2) in the            spring and early summer, becoming light pink (Plate 4, H-3)            in midsummer on the dorsal side and light green on the            ventral side. Medium prostrate hairs (U.P.O.V. — 6.1.11/1).            Relief of surface is striate. Length ranges between 5.0-11.5            cm, averaging 8.6 cm. Width ranges between 5-7 mm; mean of            5.8 mm.        -   Nodes.—Coloration is similar to internodes. (U.P.O.V. —            6.1.8/3 and U.P.O.V. — 6.1.9/2). Width ranges between 6-10            mm; mean of 8.4 mm. Buds average in size, not prominent.-   Tendrils: Intermittent, 0-0-2-0-2-0-2 (U.P.O.V. — 6.1.14/1). Light    green (Plate 1.7, I-7) except for pinkish-red (Plate 5, I-5)    pigmentation on basal 1/3. This becomes light pink (Plate 4, H-3) in    midsummer growth. Forked. Length is medium, ranging between 9 and 14    cm, averaging 10.85 cm (U.P.O.V. — 6.1.15/5). Width ranging between    1-2 mm, averaging 1.5 mm.-   Flowers: Male with fully developed stamens and reduced gynoecium    (U.P.O.V. — 6.2.1/2). Flower clusters small, ranging in length    between 3.5 and 6.5 cm and averaging 5 cm. Basal 1/3 of rachis of    reddish-pink pigmentation similar to the shoot. Calyptras light    green with reddish pigmentation on top and at base (nectaries).    Flowers dehisce at onset of bloom. RS-9 plants does not produce    complete flowers; they only contain male parts. No fruit is    produced. The average date of the beginning of bloom is May 5 at    Parlier, Fresno County, California. The period of bloom lasts 7 to    12 days, depending on the season. The flowers abscise during this    period and the flower cluster dries up.-   Leaves, blades:    -   -   Shape.—Reniform (U.P.O.V. — 6.1.22/5), entire (U.P.O.V. —            6.1.23/1). Open U-shaped petiolar sinus (U.P.O.V. —            6.1.30/2) without exposed veins (U.P.O.V. — 6.1.32/1).        -   Size.—Small (U.P.O.V. — 6.1.21/3). Length ranging between            7.6 and 10.4 cm, averaging 8.8 cm. Width ranging between 8.0            and 10.5 cm, averaging 9.2 cm.        -   Appearance.—Upper surface is dark green (Plate 21, G-7),            glabrous and shiny; lower surface is yellowsh-green (Plate            21, E-3), glabrous (U.P.O.V — 6.1 35/1) with short, white            upright hairs (U.P.O.V. — 6.1.38/3) on the veins. Veins are            light green, not prominent; reddish-pink pigmentation near            the petiolar sinus, mainly on the basal 1/5 of the inferior            lateral veins and becoming faint on midsummer growth            (U.P.O.V. — 6.1.24/3). Contour is flat (U.P.O.V — 6.1.25/1).            Surface is slightly bullate (U.P.O.V. — 6.1.26/3).        -   Dentation.—teeth wide, short (U.P.O.V. — 6.1.28/3) and            concave (U.P.O.V. — 6.1.27/1). P ≦0.25 (height/width of            serrations) (U.P.O.V. — 6.1.29/1).-   Leaves, petioles: Reddish pink (Plate 4, H-3) on dorsal (exposed)    side and reddish pink with green stripes on ventral side, becoming    light pink on midsummer growth. Medium, prostrate hairs. Length    ranges between 3.2 and 4.7 cm, averaging 3.8 cm; width is 2.5 mm    (U.P.O.V. — 6.1.40/1).-   Canes (mature shoots): Lignified, mature shoots in late summer and    fall are medium reddish-brown (Plate 7, C-10; U.P.O.V. — 6.1.42/4)    with striations (U.P.O.V. — 6.1.41/3) in the internodes. About every    5^(th) or 6^(th) striation is of dark brown color, often resulting    in 4 or 5 obviously darker striations per internode.-   Trunk: The first inner layer of old bark is slightly grayish-brown    (Plate 7, A-10). The outer layer is rough, peeling and gray (Plate    7, A-7) due to weathering and trunk expansion.

For purposes of comparison, a similar analysis of parents Schwarzmannand Ramsey performed at the USDA collection at California StateUniversity, Fresno. The following is a result of that analysis:

‘RAMSEY’ ROOTSTOCK

-   Vine: Vigorous, dense growth; upright in attitude.-   Shoots:    -   -   Shoot tip.—Half open, felty white.        -   Young leaves.—Light, yellowish-green. Medium, prostrate            hairs on upper surface. Medium, prostrate hairs on lower            surface, especially on the veins and the petiole.        -   Internodes.—Light, yellowish-green. Medium, white tufted            hairs or tomentum. Medium in length; small to medium in            diameter. Relief of surface is slightly striate.        -   Nodes.—Coloration is similar to internodes. Fewer hairs than            on internodes. Buds average in size, not prominent.-   Tendrils: Intermittant, 0-0-2-0-2-0-2. Small to medium long and    fine; bifurcated. Light, yellowish-green.-   Flowers: Female. Small, compact clusters of medium-small black    berries.-   Leaves, blades:    -   -   Shape.—Reniform to almost round, slightly 3-lobed. Petiolar            sinus deep, open U-shaped.        -   Size.—Medium to medium-small.        -   Appearance.—Upper surface medium dark green with light,            prostrate hairs. Lower surface medium green with light green            veins and moderate tufted tomentum. Contour is flat. Surface            is smooth. Dentation: teeth uniform, straight-sided to            slightly concave, shallow and distinct.-   Leaves, petioles: Light, yellowish-green with tufted tomentum.    Medium in length.-   Canes (mature shoots): Lignified, mature shoots in late summer and    fall are brown with some darker striations in the internodes.    Numerous short to medium lateral shoots are present. Notable    differences between ‘RS-9’ and ‘Ramsey’ include: ‘RS-9’ has    horizontal vines whereas ‘Ramsey’ has vines upright in attitude. The    flowers of ‘RS-9’ are male whereas the flowers of ‘Ramsey’ are    female. The leaf blades of ‘RS-9’ are large whereas those of    ‘Ramsey’ are medium to medium-small. ‘Ramsey’ shoots (internodes and    nodes) and young leaves are light, yellowish-green; ‘RS-9’ young    leaves have bronzing on the tips of the serrations, and the shoots    are reddish on the dorsal side in the spring, becoming light pink in    midsummer.

‘SCHWARZMANN’ ROOTSTOCK

-   Vine: Vigorous, horizontal in attitude, climbing readily on support    wires.-   Shoots:    -   -   Shoot tip.—Closed, shiny green.        -   Young leaves.—Light, yellowish-green. Upper surface            glabrous. Sparse, white, prostrate hairs on the petiole and            the main veins on the lower surface.        -   Internodes.—Light, yellowish-green with violet-red and green            stripes on the upper side. The red coloration becomes more            faint in mid to late summer growth. Very sparse, white            prostrate hairs. Medium in length and diameter. Relief of            surface is slightly striate.        -   Nodes.—Coloration is similar to internodes. Glabrous. Buds            average in size, not prominent.-   Tendrils: Intermittant, 0-0-2-0-2-0-2. Fairly long and fine,    bifurcated. Light, yellowish-green with violet-red coloration,    especially on the branches.-   Flowers: Male.-   Leaves, blades:    -   -   Shape.—orbiculo-reniform, entire or slightly 3-lobed.            Petiolar sinus wide U-shaped.        -   Size.—Large.        -   Appearance.—Upper surface is glabrous and medium dark green.            Lower surface is glabrous and medium light green with short            hairs in the veins. Occasional light pink coloration on the            main veins at the petiolar junction. Contour is flat.            Surface is slightly bullate with more puckering at the            petiolar junction. Dentation: teeth irregular, slightly            convex, medium large and sharply pointed.-   Leaves, petioles: Light, yellowish-green with light red coloration,    especially on the upper side. The coloration is more faint in mid    and late summer growth.-   Canes (mature shoots): Lignified, mature shoots in late summer and    fall are medium reddish-brown with striations in the internodes.    Strong and long lateral shoots are present under high vigor    conditions. Notable differences between ‘RS-9’ and ‘Schwarzmann’    include: ‘RS-9’ has half open, downy white shoot tips whereas those    of ‘Schwarzmann’ are closed and yellowish-green. ‘RS-3’ has small    leaves whereas ‘Schwarzmann’ has large leaves. ‘Schwarzmann’ leaf    blades are orbiculo-reniform, sometimes slightly 3-lobed; ‘RS-9’    leaf blades are reniform in shape and entire.

1. A new and distinct variety of grape having the characteristicsdescribed and illustrated herein.